Control apparatus



Jan. 17, 1959 I c, DAVIS 2,495,169 CONTROL APPARATUS Original Filed April 5, 1941 $7.] J1EE INVENTOR s V fia/ /Z 6.17am

ATTORNEYS Patented Jan. 17, 1950 UNITED STATES FATENT OFFICE CONTROL APPARATUS Ralph C. Davis, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio 2 Claims.

This invention relates tocontrol apparatus, and has especial relation to pressure operated control devices adapted, in turn, to operate pressure operable means and regulate the conditions to which a given apparatus is subjected. This application is a division of my copending application Serial No. 386,692, filed April 3, 1941, now Patent No. 2,354,429 granted July 25, 1944.

One example of use of control devices of the nature covered by the present invention is in the vulcanization of pneumatic tires in jacket molds. During vulcanization, it is usually desirable to vary the pressure and temperature within the mold, first by progressively increasing same in several steps, holding the maximum temperature and pressure obtained for a given interval, and then reducing the temperature and pressure within the mold in several steps. With the usual type of controller devices, it has been difiicult to efiect an accurate, rapid control, in reducing the temperature of the mold in the last stages of vulcanization.

The general object of the present invention is to provide an improved control device adapted to facilitate controlling the temperature or pressure of a given apparatus to the desired value.

A further object or the invention is to provide a simple, inexpensive, adjustable control device which is sturdily constructed and adapted to give a maximum of service with a minimum of maintenance thereon.

The foregoing and other objects will be manifest as the specification proceeds, which specification is described with reference to the accompanying drawings, in which:

Fig. I is a vertical section of a control device embodying the invention;

Fig. II is a section taken on line II-II of Fig. I;

Fig. III is an enlarged vertical section taken through the valve or" the control of Fig. I;

Fig. IV is a section taken on line IVIV of Fig. III;

Fig. V is a diagrammatic view of apparatus embodying the invention and for practice of the method of the invention; and

Fig. VI is an enlarged view showing the mechanism of valve it of Fig. V.

The general aspect of the present invention is best illustrated by Fig. V, and this includes the apparatus or article to be controlled in accordance with the invention, in this instance, a jacket mold l0. Steam or other heating fluid is introduced into the mold ill through a pipe H having a shutoff valve l2 therein, which pipe I l connects to any suitable source (not shown.) 01 Siteunder pressure. A temperature or pressure control and/ or indicator 13 of standard construction is provided and is connected to the mold in by a pipe or other means it, whereby the temperature of the mold ii) is accurately recorded on the indicator l3. A pipe l5 connects to the indicator l3 and is connected to a suitable constant pressure source (not shown) which, in this case, was 20 pounds per square inch of air pressure. Thus, the temperature indicator I3 is constructed and arranged so that its operation is controlled by the temperature of the mold It in relation to that desired in the mold, at that given time. The indicator l3 opens or closes a valve 13a, associated therewith whereby the air pressure in pipe l6 leading from the temperature indicator it can be varied from zero to 20 pounds,de-, pendent upon the position of the valve l3a. A mechanism which is satisfactory for operation of 13a is shown in Fig. 3, of the Karl H. Hubbard Patent No. 2,076,641. The pipe IS, in turn, connects to a pressure controlled. valve ll that is in the steam line I I, whereby the valve I1 is opened or closed, dependent on whether there is a low or a high pressure, respectively, in the line It, so that steam is permitted to flow through, or is prevented from flowing through the line H to the vulcanizer Hi.

In order to reduce the temperature of the mold it rapidly, when desired, a three-way valve I8 is also connected in the steam line H between the valve Ill and the mold. This valve l8 connects to a pipe [9 that leads to a sewer, or other exhaust means. The valve 18 is constructed and arranged so that it either permits flow of steam through the line ll to the mold H3, or else permits flow of steam from the mold Iii to cheer;- haust pipe [9. The positioning or operation of the valve 18 is controlled through a controller unit generally indicated 2%, which connects to the valve it by a pipe 2i. The controller unit 20 is connected to the 20 pound air supply pipe it by a pipe 22, while the controller also has a variable supply of air pressure connected thereto through a pipe 23, which pipe connects to the pipe l6, whereby the pressure in the pipe 23 is dependent upon the conditions existingin the mold Iii in relation to those predetermined conditions set up as desired in the mold at that point in the vulcanization cycle. The controller unit 20, as will hereinafter be pointed out-in detail, is designed so that the variable pressure in the line 23 opens the valve I3 and connects the mold It to the exhaust line H] when the temperatur in the mold is above that predetermined value desired at that instant. At other points in the vulcanization cycle when the mold is at substantially the temperature desired, or when it is below the desired temperature, then the controller :20 maintains the valve '|8 in such a manner 'that-steam readily passes therethrough to the mold in in order to raise its temperature. Hence, by provision of the controller 20 a rapid, automatic means for lowering the temperature of the mold I when the temperature thereofis stepped down sharply, or at-Tany other .desired time. is provided by the controller 20.

Figs. I through IV show the specific construction of the controller device -20, which includes a frame 30 which has an apertured block 3| at the upper portion thereof, to-which:block 3| the pipes 2|, 22, and 23 connect to supply the compressed air to the controller in order tooperate same. The device 20 includes a cover 30b. "The block 3| has apertures 32, 33 and 34 formed therein "with the variable pressure 'control pipe 23"conn'ecte'd'to the aperture33 and'pipes'22 and 2| to apertures 32 and 34, respectively. A bellows '35 is connected to the aperture 33 and rec'eives air 'from'the line 23. The bellows3'5 is of any standard construction and exerts'an appreciably larger "force atits 'freeend than the "force of pressure exerted on the bellows by the fluid fromthe line 23. A split'block, or other suitablepres'sure transmitting member 36 is carried bythefree end'of the bellows whilea'ball bearing"37 "which contacts a lever33 that ispivotally mounted-at one end on'a'bracket 30a forme'don the frame '30, is mounted on the'loweriportion of the split block. Theball bearing 31 facilitates sliding movement of the block on the lever "38. Thelver' 38 'is mountedito have pivotal movement 'in a given 'Iplane and is in operative rela- -ti'onshipwith a valve,'indicated generally at 39, :t'vlii'ch'ispositione'd Qn'the'frame BQ. "The valve 39"is.'con'necte'd to the block 3| and thereby to theIpipes 2| and'22 by means 'oftubes 4| and "42, respectively, whichconnect to a manifold 43 that is secured to'thev'alve'39 by screws 40.

"The valve includes a valve body'44 inwhich a movable plunger '45, having longitudinally extending ribs '45a on its outer surface, isreceived. ;The valve body 44 has. an axially extending bore 46 formed therein which has a shoulder 46aformedtherein. One-end of the bore 46is-enlarged rat 4'Land is provided with a threaded surf-aceto engage with a supplementalvalve housing 48. conduits lifl -and49in the valve body connect the bore 45 to the-tubes 4| -and42, respectively. The valvehousing 48 has an axially-direeted-bore=|:formed therein anda-a shoulder 5 Ia sis formed-in-this-bore adjacent the valve-body '44. Exhaust openings 52 extendfrorn the-bore -5| tethe -periphery of the valve housing-48. The valve-i39 is completed byan outer valve plunger i53 which -is secured to, or integral'withamember 54 -which=is-snugly received Within-the bore 5|. -Th-lsi0lit6r -valve -plunger connects to -'.the inner *valvei plunger-45103 means of anauxiliary plunger 55,=-which also has a corrugated or'ribbed outer .=periphery, and which is on the opposite 'side of tlre'rshoulderifi ta from' the 5 member 54. In some casespitmay :be desira'ble to formiplungers '45 and 553as 'a unit,i 'although in the construction shown the :plun'gers are separate but in contact 'at all tirnes'in the valves operation. conic'ally shaped-seating surfaces- 45b and'55a areformed the spaced 'ends of l the plungers 45 and 5 5, re-

all

shoulders 46a and Ski, respectively, in order to form seals in the bores 46 or 5|, when desired.

Fig. III shows that, normally, the fluid pressure led to conduit 49 by the tube 42 forces the plungers 45 and 55 to their outermost positions with'respect to the valve 39 and, when in such position, the valve plunger 55 is seated on the shoulder 5m, whereby the conduit is formed throughithe valve from the inlet conduit 49 to the outlet conduit 50, which, in turn, enables air "supplied to the controller 20 through the pipe 22 to pass'therefrom through the pipe 2| and maintain the valve H3 in its normal position whereitis open-to line H to permit passage of steam. However, when the valve plungers 45 and55 are movedto their innermost positions with relation-to the valve, then the surface 45b seats upon the shoulder 46a and seals the conduits 49 and 50 from each other. This enables gas or fluidunder pressure in the pipe 2| to escape from the valve through the escape ports 52, thereby changing the position of the valve H! to shut'olfflowlof steam to the mold and permitting exhaust of gas 'or steam from the mold M to the sewer pipe 19.

'To prevent undesired or improper movement of the valvelplunger 53, yieldable variable pressure-meansfil areassociated with thelever 38 in the same manner as the plunger 53 with relation to .the force exerted on the lever 38 through the bellows "35. That is, thepressures set up by the pressure member 6| and'the plunger 53 are in opposed relation to the pressure exerted on the lever '38" by'the bellows 35. The pressure membertLmay include a housing 62 that is carried onthe frame '30 with aspring 63 being received in and axially compressed any desired degree in the housing by a threaded set screw 64 which engages --with"a threaded end of the housing. A .pin 65 extends 'from the housing 62 withthe pin having a head 66 that bears upon the inner surface. of the housing. The pin 65 is maintained inaposition extending from the housing by'the spring 63. ThepinBB-normally engages with a set screw fi'l'carried by the lever '38, whereby a vyieldable -pressure is set up on the lever 38. A motionlimiting set screw 68 is also engaged with the lever-38 and is adapted to bear upon one end ofithe housing 62 and limit movement of the lever 38 toward the housing whereby the forced movement ofthe plunger 53 is also limited.

'In'operation, as pointed out above, it will be seen that the variable pressure set up upon the bellows 35 can be used to change the position of thevalve 39 and thedesired temperatureand/Or pressure conditions on the controlled apparatus can *be established. For example, a predetermined pressure can be established at which the valve 39-is-to operate. Then the set screw is adjusted to set up suchpressure upon the pin 65, whereby normal pressure upon the bellows 35 is not'sufficient to'force the lever 38 downwardly and change the position of the valve 39. However, when suflicient pressure is set up in the -pipe23, as-when the temperature in the mold W is too high, then the bellows will force the lever to movev downwardly and will then move the plungers 45 and 55 of the valve to their lower seating position and break the passage formed between the'inlet and outlet conduits 49 and 5E! and form a passagebetween the outlet conduit 50 and the exhaust conduit 52, whereby the position ofthe valve 18 is changed, steam exhausted s'pectivelmarid are adapted tobe seated upon' the fr0m the mold. ||J,'and the desired temperature set up in the mold. Then, the pressure on the bellows 35 is reduced and the combined actions of the pressure exerted on the bellows 35 by the valve 39, through the plunger 53, and the compression of the spring 63 force the lever 38 to its uppermost position, whereby the setting of the valve I8 is changed and steam can be introduced into the mold to maintain its temperature at the predetermined level.

The detailed description of the particular embodiment of the invention illustrated and described herein is not to be construed as limiting the invention thereto. The invention includes all features of patentable novelty residing in the foregoing description and the accompanying drawings.

What is claimed is:

1. A control device adapted to be used in conjunction with an installed control whereby the performance of said installed control is affected, said device comprising a frame, a bellows carried by said frame and designed to have a variable pressure exerted thereon, a lever pivotally mounted upon said frame, means carried by said bellows and bearing on said lever, a valve having inlet, exhaust and outlet openings therein positioned upon said frame adjacent said lever, said valve including a movable element extending therefrom adjacent said lever and contacting same in opposed relation to said member, the position of said movable element determining whether said outlet opening connects to said inlet or exhaust opening, and yieldable adjustable pressure means associated with said lever in opposed relation to the first said means to limit the normal position of said lever with relation to said movable element, said valve inlet being adapted to have a fluid under constant pressure supplied thereto to retain said movable element normally in connecting relation between said inlet and outlet openings, but said bellows being adapted to exert sufficient pressure upon said lever under predetermined pressure conditions in the bellows,

to change the position of said lever, move said movable element, and connect said outlet and exhaust openings.

2. In a device for operating control apparatus, a frame, a bellows carried by said frame and adapted to receive a variable pressure, a lever pivotally mounted upon said frame, said bellows being operatively associated with said lever, a valve having inlet, exhaust and outlet openings therein positioned upon said frame adjacent said lever, said valve including a movable element extending therefrom adjacent said lever and contacting same in opposed relation to said bellows, the position of said movable element determining whether said outlet opening connects to said inlet or exhaust opening, and pressure means associated with said lever in opposed relation to said bellows to limit the normal position of said lever with relation to said movable element, said bellows being adapted to exert sufficient pressure upon said lever to change the position of said lever and move said movable element under predetermined pressure conditions in the bellows.

RALPH C. DAVIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 17,558 Hauxhurst Jan. 7, 1930 681,172 Koenig Aug. 20, 1901 809,590 Watson Jan. 9, 1906 1,017,178 Selin Feb. 13, 1912 1,358,193 Fulton Nov. 9, 1920 1,480,126 Sullivan Jan. 8, 1924 1,618,815 Cory Feb. 22, 1927 1,658,382 Kimball Feb. 7, 1928 2,099,244 Temple Nov. 16, 1937 2,165,518 Stolz July 11, 1939 2,232,219 Dueringer Feb. 18, 1941 2,256,165 Mastenbrook Sept. 16, 1941 

